How to trigger something when a game property equals a (certain value)
The script is checking if prop is an integer equal to 50, but the property is actually a string.

Solution 1

Change String to Integer in the Properties panel

Solution 2

Change

if myprop == 50:


To

if myprop == '50':


Going forward if you enable the console (Window -> Toggle System Console) it will let you know when these sort of errors happen.